Artificial fog generator



W. J. BESLER ARTIFICIAL FOG GENERATOR March 3, 1953 Filed Nov. 12, 19474 Sheets-Sheet 1 WILLIAM .J. 5:51.52.

INVENTOR.

BY rr 5 A {for/My March 3, 1953 w. J. BESLER 2,630,412

ARTIFICIAL FOG GENERATOR Filed Nov. 12, 1947 4 Sheets-Sheet 2 76 7.4?WILL/RM 55.54am

INVENTOR.

By ALMA,

Alfarnoy March 3, 1953 w. J. BESLER ARTIFICIAL FOG GENERATOR 4Sheets-Sheet 3 Filed Nov. 12, 1947 WILL/M .1 but.

INVENTOR.

Afforncy m H MM 0 m mm 3 s 6 0w W k. a a u m 1. n 2 a M a 2 m J m v J Mllwil. III, 11 4 I w 9 l M M 4 1 u 1 6 I R W W W N m u 7 A 4' I 7 ,lh Em a 5 B m 7% H B F j a, W L m f 5 k 7 w I 6 7 :1 H 8 IO o H T 6 4 wan fif i v 1 7 M Z 1 6 4 r 1 March 3, 1953 Flled Nov 12, 1947 Patented Mar.3, 1953 UNITED STATES PATENT OFFICE ARTIFICIAL FOG GENERATOR William J.Besler, Piedmont, Calif.

Application November 12, 1947, Serial No.- 785,351

3 Claims. 1

an obscuring fog which may be breathed by humans and animals withouttoxic effects or respiratory depression.

Another object is to provide a portable, fast acting means forgenerating a maximum volume of fog in the minimum of time while at thesame time requiring a minimum of effort and attention by the operator.

The invention has peacetime uses as well and it is an object to providea device which can be operated, as an insecticide disseminator or as anartificial aerosol for the protection of crops of all kinds.

Another object is. the coordination of the fuel supply to the engine andthe generator, and the utilization of the products of combustion of bothin a most efiicient manner;

It is also an object of the invention to provide thermostatic meanswhich may be set at amaximum operating temperature as indicated by thetemperature adjacent the outlet of the generator and to automaticallycut off the fuel to the burner when the temperature reaches thepredetermined setting and restoring fuel and fire when the temperaturedrops below the setting.

Further objects are to provide a construction of maximum simplicity,economy and ease of assembly and disassembly and such further objects,advantages and capabilities as will fully appear and as are inherentlypossessed by the device and invention described herein.

The invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings, and whilethere is shown therein a preferred embodimnt it is to be understood thatthe same is i1lus trative oi the invention and that the invention iscapable of modification and other uses and comprehends other details ofconstruction without departing from the spirit thereof or the scope ofthe appended claims.

In the four sheets of drawings:

Figure 1 is a diagrammatic perspective view of a fog or aerosolgenerator constructed in accordance with this invention showing thefluid flow systems, the motor unit being omitted.

2 Figure 2 is a plan view from above, of the assembled device.

Figure 3 is a side elevation of the same from the blower side.

Figure 4 is an elevation of the systems end of the same.

Figure 5 is a vertical section of the thermostatic fuel supply control.

In detail the structure shown in Figure 1 comprises the base preferablyin the form of a rectangular tank having a central partition 1 dividingit into the fuel tank 2 having the capped fill- For portability-the basetank is provided at its four corners with the handles 6 and I slidablein brackets such as 8, welded to the four corners of the base tank. Forprotection the base tank is provided with the skids 9 and H3 securedalong the longitudinal marginal edges. For anchoring the device in anygiven location, as to the deck of a ship, the bed of a truck or thelike, brackets l I are fixed to the four corners of the base tankadjacent the bottom. The hooks I2, adapted to be engaged in eyes orclips (not shown), are adjustable within said brackets II. There areseveral other conventional means for securing the device to a surfaceand any of these may be used.

lower edge welded, bolted, or secured by any other suitable means to thetop l4 ofthe base tank. The meeting edges or housing l3 and the cover I5 are flanged outwardly and held together by the tension girth [6, theends of which are drawn together by the turnbuckle ll. The cover has thetop outlets. It and IQ for the escape of the products of combustion witha minimum of glow. The housing I3 is insulated as, at 19a and itsinterior wall and bottom form combustion air space 20 (see Figure 3)between the insulated housing I3 and the inner cylindrical combustionchamber wall 2|. This wall 2| is supported at its top by outwardlydirected annular flange 22 interposed between the flanges of the housingIt and cover. 55 and secured by the single tension ring l6. The floor 23of the combustion chamber proper 2m.

has an outturned peripheral flange secured to the lower edge of wall 2L.Depending from the floor 23 of the combustion chamber proper Zla andabout the central opening 211) in said floor, is the preliminarycombustion and mixing chamber 2 4, closed at the bottom by plate 24a andhaving louver openings 26" in the circular wall 26.

The burner means comprises the fueloil burner 25: secured to a burnerpIate'- attached to the The cylindrical generator housing l3 has itsoutside of the casing or housing It. The burner produces a torch-likeflame in the preliminary combustion chamber 24 that is open at the top 2lb to the combustion chamber proper 2 in above. The products ofcombustion fiow upwardly through the chamber and out through the topopenings l8 and H). The fuel atomized into the burner 25 is ignited bythe spark plug 25.

The fog generating means comprises the assembly of flat horizontallyspiraled or pancake coils 21 to 32 inclusive, interconnected to form acontinuous tubular generator. The uppermost coil 21 is the inlet for thevapor forming components which successively flow downwardly through theseries of coils to the lowest coil 32 nearest the flame in thecombustion chamber 2w. 7 The lowest coil 32 discharges at 33 into thehorizontal run of tubing containing the thermostatic tube 34. Fromthence it goes to the vertical portion 35 passing upwardly substantiallyon the axis of the series of coils, and outwardly above coil 21 throughthe cover 15, to the arcuate and perforated vapor jet 35 through whichthe generated vapor is ejected and expands into a fog in surroundingatmosphere, all as more fully explained hereinafter.

The motive unit, preferably a relatively small internal combustion motor31, is mounted upon a platform on the top M of the base tank. The motorshaft is coupled to and directly drives the suction fan (notshown)mounted within the fan casing 38. This casing discharges tangentiallyand directly through the insulated casing 13 and into the air space 20thence through the louvers 26 in the wall 26 of the preliminarycombustion chamber 24, causing a whirling turbulence and distribution ofthe air. The engine exhaust is delivered to the burner 25 in thecombustion chamber 24 which heats the burner and insures ignition incold weather. Combustion takes place in combustion chamber 24 andcontinues in combustion chamber 2 la where burning is completed. Theproducts of combustion within the generat-or then pass upwardly aroundthe spaced vaporizing coils 21 to 32, which absorb the heat from theproducts of combustion, and are dissipated to atmosphere through outletsI8 and I9 in cover IS.

The shaft of the motor 31 projecting on the r side opposite from theblower, has a sprocket thereon for driving the sprocket chain 39encircling the sprocket 40 on the countershaft 4! extending between thefog oil pump 42 and water pump 43 mounted upon the base fuel tank 2.

The conventional pulsating diaphragm servomotor fuel pump 44 is a partof and driven by the motor 31. It lifts fuel from the tank 2, throughthe pipe 45 and the strainer 45 and discharges it into the feed line 41supplying the motor carburetor 48, having a regulating float valvetherein as usual. Since in the device shown, gasoline is the fuel forthe generator, 3., statically controlled valve 49 is providedin the line41 (see Figure 1) before it reaches the manually controlled burner valve50. From 50 the fuel flows through the T fitting 5| to the pipe 52 thatdischarges into the burner tube 25 through a restricted orifice, whereit is warmed and vaporized by the exhaust gases flowing from the motorto the burner through the exhaust pipe 53 and mixed with the swirlingcombustion air entering through louvers 26. The fitting 5| has the riser54 extending upwardly into the fuel levelchamber 55 which functions asan overflow, leading back to the fuel tank 2 through return line 56.Chamber 55 has the duct 51 leading from the blower casing 33 formaintaining a plus atmospheric pressure in the chamber 55 to overcomethe air pressure in the burner tube which would tend to prevent gasolinefrom entering the burner. The above fuel system supplies the motor 31and the burner 25 with both an automatically and manually regulated flowof combustible fuel.

The fog oil system comprises a pump 42, which is here shown as a rotaryor gear pump although any suitable type may be used, having the inletpipe 58 connected with the flexible inlet hose 59, which in turn isprovided with a nozzle pipe 50 for introduction into the source of fogoil supply, which may be a separate drum of fog oil.

When not in operation the hose 59 rests in the bracket 6| on the side ofthe generator easing IS. A fog oil filter 52 is interposed in the intakeline 58 ahead of the fog oil ump 42.

The pump 42 discharges through the pipe 63 '(see Figure 1) through thethree-way valve 64 and into the generator inlet pipe 65 leading to thetopmost coil 27 in the heating chamber 21 through the check valve 55.The three-way valve 64 has the handle 61 for opening or closin thedischarge from the pump 42. has the bypass 68 leading back to the inletside of the pump, for balancing the pump pressure while idling, with thehandle 6'! in the vertical or "off position shown.

' The water pump 43 here shown preferably as .a plunger pump is drivenby the shaft 4! and lifts water from the water tank 4 (see Figure 1)through the pipe 10, the strainer H, the pipe 12 into the pump throughthe check valve 13, and discharges through the check valve 14 into thepipe 15. This pipe feeds the water through the check valve 16 into thegenerator inlet pipe 65 where it mixes with the fog oil flowingtherethrough from the pump 42 as previously described. The volume ofwater supplied is constant at a given engine speed and mixed with thefog oil in line 65 before entering the generator in proportion to thefog oil being pumped at the same engine speed. Normally the water to fogoil ratio is approximately 10:90.

The water and fog oil mixture enters the up-l permost coil 2! of thegenerator. As it passes through the coils 2'! to 32 the temperature israised to around 900 F. thus vaporizing some result is an immediate,dense, persistent cover- 2 ing fog which is neither inflammable norinjurious to respiraticn. The water supplied not only produces thevehicle, superheated steam, for the dispersion of the fog oil particlesbut performs several other functions. Its presence helps prevent thecracking of the fog oil and reduces the deposition of solids,particularly carbon, within the tubes. The relatively large vol- This'valve.

stee s-ta ume of steam helps to scour the tubing and provide efllcientheat transfer. 7

The fog oils used are usually a highly refined lubricating oil or anyother type of oil conform- Referring to Figure the thermostatic valve49' is introduced to control the supply of fuel to the burner 25- inorder to automatically maintain the proper vaporizing temperature in thecombustion chamber 2 l e.

The fuel valve 49" has the fuel inlet 11 and outlet T8 closed by thediaphragmto' under spring pressure on the valve head 19- above theoutlet 18. The valve head has its stem 8'! in contact with the" bellcrank 82 which is pivoted at 83" and depressed by the spring 84'attached to the bottom of the surrounding case 85. The entire fuel valveassembly is mounted at the end of the expansion tube 34 outside thecasing. The arm 85 of hell crank 82* bears against the thermal sensitiverod 87* composed of quartz or the like which extends through andisflsecured' in the tube 34. It is apparent that by adjusting the lengthof the stem 8| the closing of the fuel valve can be accomplished forthe. temperature required. As the temperature approaches the settingonly enough fuel willpass through the valve 49 to maintain thevtemperature of the setting.

The. invention operates substantially as follows: The. motor 3.! is.started first and run for a. few moments. so. that the exhaust gaseswill preheat the. burner 25 before the. fuel manually turned on at 5.0.As soon as the motor 31 starts, then all of. the elements driven by italso begin to operate. The water pump driven by the motor delivers waterto. the. inlet of the generating coils 21-32 before the burner isignited. The pumping of water to the generator can be checked by openingdrain cock 88. The blower is started and air is supplied to thegenerator. The motor fuel pump 44 forces gasoline fuel through the fuelcontrol valve 49 to the fuel valve 50. Within a few seconds after themotor is started the valve 50 can be opened and the vapor burner ignitedby switching on the spark plug 25 in the motor ignition system.

When the burner fuel valve 5!] is opened the fire will start and in afew seconds will automatically diminish to low fire. The device is thenready for the admission of the fog oil. The fog oil handle 6'! is moveddownwardly to the horizontal or on position. When the valve 64 is openor in the on position the pump 42 pumps the fog oil through the intakepipe or nozzle 80 through the flexible hose 59 and through the strainer62. It is delivered by the pump to line 63 through check valve 66 whereit is mixed with water from line in line 65 just prior to entry into thegenerator. By the time the motor is started and the fog oil handle ismoved to the on position the fog oil pump 42 is in operation pumping fogoil from the source of the supply through the strainer 62 to theshut-off valve 64. When the handle 61 is in the off position the fog oilis diverted back to the pump through by-pass line 68.

The mixture of fog oil and water as it enters the first coil 21 passesin substantially a counterflow path with respect to the products of com-6;; bustion, from: the com 1' ion chamber titan-and the waste. productsof combustion pass. out through the deflected: path at openings I18 andti.

The unit. comes: up. to temperature very quickly and as the. tube 34;expands with. the heat: it. will expand more. rapidly than: thethermostatic. els ment 31: secured at its outer end tsee Figure 5). The:expansion oi this tube. moves the arm: 06. away from the end of theelement 31 increasin the tension of the spring 80. on. the stem. 81;,thus reducing the. flowof fuel. through the valve 48- to the. burner. intum decreases; the tomb peratmze within the combustion chamber 2 I a andfurther automatic control, is maintained. For fogging purposesthethermostat control is set for approximately 900 F. which means thatthe valve 43 will be open to permit just enough pas sage of. fuel tomaintain the. temperature at the setting. If the temperature goes higherthe ex-'- pansion of tube 34 will increase causing the thermostatic:control to close.- the diaphragm valve on its seat.

As: shown above water is supplied to the device by a positivedisplacement pump 43- which supplies enough water to theiog. oil. toaccomplish the purpose. required. It ia to be understood that it adifferent proportion or ratio requireda different water pump may beplaced in. its stead or its operation' speeded up so as to deliver thein.- creased. amount. In addition to. the other drives on the motor. 31,it. also drives a small. magneto which. furnishes the energy, to. the.spark plug 25 in the burner assembly 25... It will also. be. 1

observed that the. gasoline fed to. the. burner 25;

. is under a. constant head from the gasoline. level.-

eration in connection with the. making of fog with aerosols having aparticle size of from .1 to .03 micron radius, it has been. discoveredthat the size of the particle released is directly proportionate to theoperating temperature of the device. Thus, aerosols having a particlesize of from 2 to 10 microns radius for example, are obtained byoperating the device at temperatures from 450 to 500 F.

As has been explained before the function of the water supplied to thissystem in the operation of the device is primarily to secure enoughwater for the generation of steam which is the vehicle for thedissemination of the particles. Obviously, if the fluid put through thedevice is an insecticide, for example, which contains water in properportion, then it is not necessary to operate the water system on thedevice and the same may either be disconnected or removed withoutaltering the function or operation of the device. any event steam isproduced which is the vehicle for securing an aerosol or fog which, iffog is used, will result in a dense, persistent covering fog, or if aninsecticide is used will result in a penetrating thick fog which carriesthe lethal material to trees or crops or whatever may be the object ofthe treatment. Obviously the nozzle 36 may be adjusted by any well knownmeans to any direction desired.

This application is a continuation-in-part of application Serial No.523,292, filed February 21,

1944, now Patent No. 2,432,372 issued December 9, 1947.

I claim:

1. Fog generating apparatus comprising a coil having an inlet end and anoutlet end, heating '2: means comprising a combustion chamber and aburner therefor arranged to heat said coil by combustion :gasescountercurrently to the flow of fluid through'thecoil from the inlet endto the outlet end thereof, a fog oil pump and a water pump, meanscommunicating each pump with the inlet end of said coil to deliver fogoil and Water thereto in a predetermined ratio, an internal combustionengine for operating said fog oil pump and water pump, a fuel pumpoperated by said engine, means communicating said fuel pump with saidengine tozsupply fuel thereto,-

means communicating said'fuel pump with said burner to supply liquidfuel thereto by gravity,

preheating means for preheating the fuel thus delivered to said burnerby'heat exchange with the hot combustion gases from said engine,

thermostatically controlled valve means control-.

ling the amount of liquid fuel delivered to said burner, saidthermostatic means being in heat exchanging relation-to the fluid in theoutlet of said coil and being responsive to the temperature.

thereofto control the amount of fuel delivered to said burner therebymaintaining said fluid'at a predetermined temperature.

2. Aportable self contained fog generating apparatus having a heatexchange unit and auxiliaries, said, heat exchange unit comprising incombination a coil having an inlet end and outlet end, heating meanscomprising a combustion chamber and a burner therein located relativelyto saidcoil so that combustion gases from said burner will flowcountercurrently to fluid flowing fmm the inlet end-to the outlet end ofsaid 8. exchange unit and within said coil adjacent its outlet endoperativelyconnected to said fuel feed means to control the flow of fuelto said burner thereby continuously maintaining said fluid in said coilat a predetermined temperature.

3. Fog generating apparatus having a' heat exchange unit andauxiliaries, said heat exchange unit comprising in combination a coilhaving an inlet end and an outlet end, heating means comprising acombustion chamber and a burner therefor adapted to burn gasoline andarranged to heat said coil by combustion gases therefrom, saidauxiliaries comprising in combination pump means for pumping a mixedfluid to the inlet end -of said coil, a gasoline engine for operatingsaid REFERENCES CITED 7 The following referencesare of record in thefile of this patent: e UNITED sTATEs PATENTS I Date Number Name1,827,950 Mulligan Oct. 20', 1931 1,925,643 Ofeldt Sept. 5, 19332,128,263 Ofeldt Aug. 30, 1938 2,426,846 Roselund Sept. 2, 19472,428,580 Pennow Oct. 7, 1947 2,432,372 Besler Dec. 9, 1947 Davis Oct.12, 1948

1. FOG GENERATING APPARATUS COMPRISING A COIL HAVING AN INLET END AND ANOUTLET END, HEATING MEANS COMPRISING A COMBUSTION CHAMBER AND A BURNERTHEREFOR ARRANGED TO HEAT SAID COIL BY COMBUSTION GASES COUNTERCURRENTLYTO THE FLOW OF FLUID THROUGH THE COIL FROM THE INLET END TO THE OUTLETEND THEREOF, A FOG OIL PUMP AND A WATER PUMP, MEANS COMMUNICATING EACHPUMP WITH THE INLET END OF SAID COIL TO DELIVER FOG OIL AND WATERTHERETO IN A PREDETERMINED RATIO, AN INTERNAL COMBUSTION ENGINE FOROPERATING SAID FOG OIL PUMP AND WATER PUMP, A FUEL PUMP OPERATED BY SAIDENGINE, MEANS COMMUNICATING SAID FUEL PUMP WITH SAID ENGINE TO SUPPLYFUEL THERETO, MEANS COMMUNICATING SAID FUEL PUMP WITH SAID BURNER TOSUPPLY LIQUID FUEL THERETO BY GRAVITY, PREHEATING MEANS FOR PREHEATINGTHE FUEL THUS DELIVERED TO SAID BURNER BY HEAT EXCHANGE WITH THE HOTCOMBUSTION GASES FROM SAID ENGINE, THERMOSTATICALLY CONTROLLED VALVEMEANS CONTROLLING THE AMOUNT OF LIQUID FUEL DELIVERED TO SAID BURNER,SAID THERMOSTATIC MEANS BEING IN HEAT EXCHANGING RELATION TO THE FLUIDIN THE OUTLET OF SAID COIL AND BEING RESPONSIVE TO THE TEMPERATURETHEREOF TO CONTROL THE AMOUNT OF FUEL DELIVERED TO SAID BURNER THEREBYMAINTAINING SAID FLUID AT A PREDETERMINED TEMPERATURE.